未处理的异常：'package:flutter/src/widgets/navigator.dart'：断言失败：第 3499 行 pos 12：'!_debugLocked'：不正确。”FLUTTER

Question

I work in flutter project, and i have a problem that : the project composed from three Pages (splash.dart, login.dart, dashboard.dart), when the app launch the splash.dart page opened, and i passe the new user to login.dart page, and when he put a valid credentials i passe he to dashboard.dart page but in this second passage i got the error below "[ERROR:flutter/lib/ui/ui_dart_state.cc(166)] Unhandled Exception: 'package:flutter/src/widgets/navigator.dart': Failed assertion: line 3499 pos 12: '!_debugLocked': is not true." Also when i want to display an alert to inform the user to put a valid credentials when he put invalid credentials a got the same problem thanks in advance,

Answer 1

The method you use for page redirection should look like this:

Navigator.of(context).push(
        MaterialPageRoute(
          settings: RouteSettings(name: OtherPage.routeName),
          builder: (context) => OtherPage(),
        ),
      );

If this method doesn't fix your problem, be careful where you define it in the builder widget and make sure you don't use BuildContext in unnecessary places